It allows you to clip your tablet or smartphone to your laptop screen via a USB cable (standard USB cables you own) and in combination with Duet Display (a separate app with a small cost for laptop & iDevices), you can experience the magic world of multi screens.
Every clip comes with various thickness of rubber pieces, so to snuggly fit your device securely to your laptop screen. You then press on the clip to secure for example your iPad. Connect it to your laptop with your USB cable. Start the Duet app on the laptop and on the iPad. Bingo, you now have two screens without lag. I can doe my work on emails, while watching the news on my iPad or open my Excel spreadsheet, so I can quickly reference, without having to switch apps to do that.
I'm very pleased with this solution. The iPad stay on securely as long as you use the appropriate rubber piece and then clip it to the laptop screen. If you press the clip and then force it onto the laptop screen, it will start to very slowly slide away.
Here's a great review on this product https://youtu.be/jwhFr5Ax3Fk